LG Ultrafine 24MD4KL-B Dims after waking up with an M2 MacBook Air

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Level 1

7 points

LG Ultrafine 24MD4KL-B Dims after waking up with an M2 MacBook Air

I have an LG Ultrafine 24MD4LKB-B connected to an M2 MBA with the MBA in clamshell mode. When the brightness on the LG monitor is set to 100% and "Automatically adjust brightness" is turned off.

When the display goes to sleep, it wakes with <100% brightness, even though the slider in the control center is set all the way to the right. The only way to get it back to 100% brightness is to slightly move the slider to the left and back up to 100% again.

I also have an Intel MBP mid-year 2020 laptop with two of these monitors connected (both connected via their own Thunderbolt cable to the laptop, not daisy chained). The Intel laptop does not experience this issue.

Both laptops are running macOS 12.5.1.

MacBook Air, macOS 12.5

Posted on Sep 11, 2022 11:12 AM

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Answer 1

Old Toad

Level 10

215,664 points

Sep 11, 2022 11:24 AM in response to TrevorSeward

Although not a solution but a workaround have you tried not putting the MBP to sleep but just use the Screensaver to dim the screens. Unless you have a number of HDD (rotational drives) it's not that critical to sleep the machine.

Just some food for thought.

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Answer 2

TrevorSeward Author

Level 1

7 points

Sep 20, 2022 8:32 PM in response to Old Toad

No luck with the new Thunderbolt cable. On the Apple keyboard, I have to dim the brightness once which brings it to full brightness, and then click the F2 to get the bar to max (though it stays at the same maximum brightness the previous bar had).

Seems like an OS bug? Or monitor firmware bug.

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